Hammer wrench



July 6, 1937.

c. N. DouGLAss 2,086,261

HAMMER WRENCH Filed June 22, 1956 y 2 sheets-sheet 1 f ZL'LQQ/ 1 INVENTOR. 6am /M Dogana:

` ATTORNEY;

July 6,`1937 c. N. DouGLAss 2,086,261

HAMMER WRENCH,

Filed June 2 2, 1936 a sheets-sheet'z INV ENT OR. 6em 4! oaa @S5 ATTORNEY.

Patented JulyA -6, 1937 UNITED STATES HAMMER WRENCH lCecil N. Douglass., Aurora, Ill., assignor to Independent Pneumatic Tool Co., Chicago, Ill., a corporation of Delaware Application June 22, 1936, Serial No. 86,597

' `19 claims. (C1. 814-54) This invention relates to a portable power operated hammer wrench for applying or removing nuts of all types from bolts in locomotive work,

bridge work, structural steel work, ship yards,

automobile plants, boiler shops, and elsewhere.

The general purpose and object of my invention is to provide a strong powerful portable tool of rugged construction, but relatively light in weight, and of such shape that it can be handled and its side wall or high in the air on a structural' steel or bridge beam without' fear of displacing the operator from his position ofwork, whether tightening large bolts or nuts or removing very tight ones. l

In carrying out the objects of my invention the general principle as to the shape of an ordinary Wrench has been followed, that is, the main body of the wrench containing the spindle and the driving means therefor and the controlling handle by which the wrench is supported in the hands of the operator are in substantially right angular relation. The advantage of this constructionis that nuts can be applied or removed by power with the same ease in close corners and conned spaces as in more open quarters.

Another advantage of my improved construcl tion, especially in structural steel and bridge work is that the operator can hold his body up against the wrench and thus be close to the work with noturning effect or torque transmitted from the spindle or its driving means to the housingof the tool. The operator can rest his body against the tool without either resisting any torque str'ain or being subject to a possible displacement from his standing position by thevtorque exerted by the power element of thetool against the spindlein setting or removing a nut or a bolt.

A further object of my invention is to employ a conventional type ofpneumatic'riveting or chipping hammer as the power element for the wrench and utilize the powerful and rapid blows of such hammer to rotate the nut driving spindle of the wrench.

' A further object of my invention is to impart the blows of the hammerto the spindle throughv a driving member which is revolubly mounted with respect to the spindle. The driving member has a releasable clutchconnection with the spindle so as to positively interconnect the driving member to the spindle when the driving member is 5 turned in one direction by the hammer blows and to release the driving member from the spindle Y when the driving member is turned in the oppoA site direction to reset the clutch connection fol-' lowing the blows of the hammer on the driving 10.

opposite ends of the spindle accessible for receiving a nut driving socket whereby one end of 'the spindle may be used for turning on a nut and 15. y

the other end ofthe spindle may be used for turning oft a nut by merely inverting the wrench.

Other and further objects of myl invention will appear from the following specification taken in connection with the accompanying drawings, in which;

'Fig. 1 is a side elevational view of my improved hammer wrench showing the nut driving socket at one end of the spindle in section and applied to a nut to be turned.;

Fig. 2 is 'an enlarged longitudinal sectional view, with parts in elevation, of the wrench end of the tool and the adjacent portion of the barrel of the pneumatic hammer which operates the wrench; Fig. 3 is a similar sectional `view of the other end of the pneumatic hammer, showing the dis-- tributing and the throttle valves for controlling the supply of compressed air to the barrel of the I Y Fig. 5 is a vertical sectional view, with parts in elevation, taken on line 5-5 of Fig. 4;

, Fig. 6 is a horizontal sectional view taken-on line 6 6 of Fig. 5; and

Fig. 7 is a sectional view taken on line 1 1 of Fig. 5 to show the locking arrangement for the protector cap,v the latter being removed from the In the drawings, I indicates the wrench housing and 2 the-barrel of a pneumatic hammer secured to the wrench housing for operating the wrench mechanism insaid housing. The hammer v is secured to the wrench housing ,by having Vthe forward end of the barrel 2 externally threaded as ata-3, and screwed into an internally threaded socket extension 4 at vone side of and formed in'-A tegral with the wrench housing. as shown in Fig.

2. A set screw 5 (Fig. 4) locks the barrel in the socket `4 after the parts have vbeen tightly screwed together.

Except for a by-pass arrangement to be hereinafter described, the pneumatic hammer is ofthe conventional riveting or chipping hammer type. Its hammering piston 6 is reciprocated in the barrel 2 by compressed air admitted alternately to the opposite ends ofthe barrel by an automatically acting valve mechanism 'I located at the inner` end of the barrel, as shown 'in Fig. 3.

The ,hammer has a throttle assembly of the customary type secured to the rear end of its barrel 2 to control the supply of compressed air to the barrel. Said valve assembly embodies av throttle valve 8 slidably mounted in the support 9 and normally biased to a closed position by a spring 8a as shown in Fig. 3. The valve 8 is moved to open position by a sleeve I0 rotatably mounted on the support 9 and having a pin and cam slot connection with the valve 8 as usual in assemblies of this character. The sleeve I0 is grasped and turned by the hand of the operator holding the tool to open the valve. The sleeve I Il must be held in valve-open position to keep the tool in operation, the valve closing automatically when the sleeve is released. `The support 9 is hollow to supply compressed air tovthe 'barrel from a supply hose connected with the support 9 through a nipple II at the outer end of said support as shown in Figs. 1 and 3.

Supported in the Wrench housing I is a rotary spindle I2 and a cooperating driving member I3. The spindle I2 is journaled in the wrench housing in roller bearings I4,l I5 adjacent the. opposite e'nds of the spindle as shown in Fig.. 5. The driving member I3 is in the form of an impact collar revolubly mounted in the Wrench housing about the spindle I2 and having an anvil projection I6 Jn its outer periphery and ratchet teeth II on its inner periphery. The spindle I2 carries a "number of pawls I8 cooperating with the teeth I'I to provide a releasable clu'toh connection between the ,collar and the spindle as will herein# after more fully appear. The pawls I8-are pivotally mounted at their inner ends in semicircular grooves or sockets I9 in the spindle and are maintained in engagement with the teeth Il bore or socket 22 provided in` thespindle for the associated plunger, as shown in Fig. 4.

l' The driving member or collar I3has rotative support in the wrench housing I in annular chamber 23 provided in saidlhousig about the spindle I 2. The anvil projection I5 extends in a. chamber- 24,also provided in the wrench housing in co-planar relation with and intersecting the .chamber 23 at one pint in its circumference as shown'in Fig. 4. -1

Extending into the chamber 24 on opposite sides blows of the hammer tothe collar I3 to turn the collar in a direction to rotate the spindle I2.

The pawls I3 are arranged to positively inter` connect the collar to the spindle when the collar receives the blows of the hammer whereby the blowsof the hammer -are utilized to' turn the spindle to .apply or remove a nut depending upon which end of the spindle is equipped with a nut driving socket 21,'as shown in Figs. l and 5.

The plunger 26 -is pressure actuated in a manner tobe presently described to constantly hold the anvil projection IIiagainst the tappet 25 to receive the blows of the hammer and to turn the collar I3 in a direction to reset the pawls I8 with respect to the teeth I'I. In this return movement of, the collar I3, the pawls I8 ratchet over the teeth I1 and the collar may thus be turned relatively to the spindle.

To insure non-rotation of the spindle I2 in the return movement of the collar I3, I provide a one-way clutch connection between the spindle and the wrench housing I. This clutch\connec tion comprises a ring 28 supported in the wrench housing about the spindle I2 at one side of the impact collar I3,. as shown in Fig. 5. 'I'he ring seats in a recess 29 in the housing and is locked against rotation by a pin 30 engaging both the ring and the housing as shown in Figs. 5 and 6.

i The innerperiphery of the ring 28 is provided with a number of semi-circular recesses 3I. Located in each recess is a roller 32. The diameter of each roller is slightly less than the radial distance between the spindle I 2 and the deepest point of the recess, 3l. The rollers are actuated upon by coiled springs 33 and plungers 34 whichhold the rollers in contact with thespindle and the cam inclines as provided by the recesses 3 I This checks the rotation of the spindle in the return movement of the collar I3, but frees the spindle for rotation with the collar under the hammer blows of the piston 6. The rollers 32 are moved by the spindle into the deepest portions of the recesses 3I when the spindle is rotated by the collar I3 and this will be apparent from Fig. .6, wherein the arrow a indicates the direction in which the spindle is rotated by the blows of the hammer. In the assembled tool an arrow appears on the outer side of the housing I in association with each end of the spindle to indicate the direction in whic'h the spindle is rotated by the blows of the hammer.

The arrow b in Fig. 4 indicates the direction in which the driving member or collar I3 is turned to rotate the spindle. It will be observed from this figure that the pawls I8 carried by the spindle I2 are set to positively interconnect the spindle to the collar when the latteris turned to rotate the spindle. To accomplish this the pawls face the direction of rotation of the collar by the ham-f mer and have abrupt shoulders at their outer ends to abut against the opposed complementary faces of the teeth Il. As shown in Fig. 4, the five pawls with which the spindle is provided are so spaced about the spindle as to come alternately into abutting or driving engagement with the teeth. I1 in the back and'forth oscillation of the collar I3. In the embodiment shown, the third pawl from the driving one is at 'the top of a tooth to'drop into driving engagement with said tooth in the turning of the collar toirelease the hold-4 ing pawl. This requires a very slight rotatiorfrdf .the collar to set a pawl, withithe result that'f"a quick interconnection isestablished and a rotary motion is insured the spindle from the oscillating motion given to the collar. I'he pawls I8 are spaced an angular distance of approximately 72 while the teeth I1 are spaced an angular distance of approximately 19. be modified considerably as long as the -angular distance between the pawls is not a multiple of Y the angulardistan'ce between the teeth I'I.

The chamber 23provides a full peripheral sup- This ratio can, however,`

70 L tion of-the .spindle are avoided and nuts can be I chamber is'intersected by the chamber 24.

port for the collar I3, except for 'the relatively small .portion of its circumference "where said The latter is wide enough to take care of the swinging movement of the anvil projection I6 in the full back and forth' turning of the collar I3. The full .swing of the collar is indicated by the maximum angle X, in Fig. 4, if there is not suiiicient load on the collar to oppose it. This maximum angle occurs when a nut is being spun on-or off its bolt. Itis arrested, however,v by the pressure on the plunger 26 and nally when the plunger strikes the bottom of its cylinder 35 with which .the housing I is provided as shown in Fig. 2. Al though the angular movement of the collar I3 is only 18 in the particular tool shown, the blows transmitted to the spindle I2 through the clutch Y device I1, I8 causes the spindle to turn as much as when it is spinning a nut on or oi a bolt.

Thus, the spindle revolves at afree speed. .of ap The cylinder 35 is connected to the live air supply for the hammer to constantly urge the plunger 26 against the anvil projection I 6 during the operation of the tool. In the particular embodiment shown, the connection is made bythe provision of connected passages in the wrench housing I and the hammer barrel 2, respectively, as shown y in'Figs 2 and 3.

As illustrated in said .iigurea the wrench housing I has a passage 3'6 connected'at one end with the cylinder 35 to the rear of the plunger 26 and at its opposite end with a channel31 in the forward end of the barrel 2; The barrel has a longitudinally extending passage- 38 connecting the -channel 31 with a passage 39 in the block of the valve assembly 1. ,A passage 40 connects the passage 39 With a channel 4I in the throttle valvev assembly about the throttle valve 8 in advance of its seat 42. The passage 40 isin the head of the throttle valve assembly screwed: into the rear'end; of the barrel 2 over and a-gainst thel block of the valve 1. -Ports 43 connect the interior of' the. valve 8 with the channel 4I, and thusa small amount of the live air is by-passed to the cylinder 35 about the throttle valve 8 whether itis open or l closed'. This insures thatthe tappet 2.5 will be in striking position for the hammer piston 6 as soon as the wrench is started. The live air enters'the barrel 2 and the passages referred/4to through the valve member 8 which is hollow and is open to the live air supply 'at the nipple I I.

As shown in Fig. 4, the teeth I-1 dojnot continue completely about the collar I3, being'omitted in the region of the anvil projection I 6, as indicatedwv at c, to give additional strength to the collar where'thegreatest stresses occur under the impacts of the hammer. I do not wish to be limited, however, to this construction as the teeth may be continued completelyabout the collar. It will also be observed fromthe .drawings that the barrel' 2 extends outwardly from the wrench housing I intermediate the ends of the spindle I2, and in substantially right angular relation thereto, thereby allowing the tool to be applied to a nut in the manner of a conventional wrench and also allowing either end of the spindle to be-used fornutturning purposes.l This simfples the device as4 complications of a design for reverse rota- -tion to engage the nut.`

pose'and are" given square' or other non-circular 21. VEach spindle end is equipped with a spring pressed detent 44 to releasably connect a socket 21 thereto as shown in Fig. 5.

A hood or cap 45 `protects the operator from the end of the spindle not being used. This cap is preferably of metal and is of a size and shape to iit over either end of the spindle 'and the adjacent portion of the'wrench housing. The cap has releasable connection with the wrench housing-*being equipped with a split ulocking ring 46 carried on the outer sidel of the cap in a groove 41 therein, and provided with diametrically dis- -posed inwardlylextending portions 48 to snap into a groove 49 in the wrench housing through ings 50 in the cap, as shown in Fig. 7.

open- For the purpose lof assembly and repair, the l wrench housing Il is made in two parts, a body section Ia and a cover section I b. The chambers.

23 and 24 are in the body section Ia and are Iclosed and completed by the cover section Ib when the latteris secured to the body section as A by fastening bolts 5I. The cover section Ib contains the ring 28 and Vits chamber 29, -and the bearing I4 for one end of the spindle I2. The

other bearing I5 for the spindle is supported in the body section la. The socket extension 4 for the barrel 2 constitutes a part of the body section la.. The cover section- Ib holds the collar I3 in its chamber 23 while the portion of the spindle I2 carrying the pawls I8 tsover the ring 28 and holds .it in the chamber 29. This section of the spindle is commensurate With the axial`dimension of the collar I3, whereby the pawls I8 may/have a v similar dimension .to adequately 'withstand the powerful blows of the hammer on the collar. The spindle is given spoke shape in. the portion referred to so that the pawls which are mounted on the spokes 52 `may move inwardly toward the spindle tov release thecollar I3. The' grooves I9 for the pawls areon the innersides of the spokes and extend completely across the same axially of the spindle whereby the pawls may have the di- A operator and when turning on and tightening a nut the socket 21 is connected with the spindleend which rotates. toward the right as shown in Fig. 1. In this figure the nut is marked 53 and the bolt o n which the nut is-to be turned and tightened is marked`54. When removing or unscrewing a nut, the socket 21 is fitted on the other end of the spindle and the tool is held in a posi- The direction arrows marked on the wrenchhousing facing the opposite lends-of the spindle/indicateto the operat which end of the spindle to use. l

When the socket 21 is applied over the nut, the compre sed air to the hammer is turned on at the valveV v and the piston 6 is reciprocated in the barrel 2 to deliver blows on the collar I3 at its anvil projection' I6. The collar I3 will be oscil- &

lated back and forth through the action of the tappet 25 and the plunger 26, and the spindle I2 will be rotated to drive the nut. When the nut collar I3 decreases and the full strength of the blows are delivered to the spindle directly through the pawl I8 in driving engagement therewith. It

is not necessary for the collar I3 to be moved far enough by each blow of the hammer to drop the succeeding pawl into driving engagement with a tooth I'l. The piston 6 can deliver any number of blows on the same pawl until the spindle is forced to Iturn sufciently to drop another pawl into driving position. Due to this action, a very large nut can be tightened or a very tight nut can be removed by simply allowing the hammer to de` liver blows long enough on the anvil projection I6. The plunger 2E being under a constant pressure during the operation of the tool holds the anvil projection I6 in position to receive the blows of the hammer and also to automatically reset the pawls.

The wrench shown is of a size to apply and remove nuts from bolts from diameter to 11/2" diameter. For this size of wrench a hammering mechanism is employed delivering approximately 1800 blows or strokes per minute. For a smaller size wrench blows as high as 4000 per minute may be used while for a larger wrench the number of' blows may be as low as 1200 per minute. The structural features of the wrench remain the same and the action described imparts powerful l impacts to the anvil projection I6.

All torsion developed by the impacts or blows of the hammer are absorbed in the tool thus relieving the operator of these strains and .permitting him to actually lay right on the nut and have complete control of the tool. When a nut is unusually tight and slow to start running, the tool being in wrenchform provides the operator with the necessary leverage to start the nut. With all torque strains eliminated it is unnecessary for the operator to frequently stop the tool for relief when using the wrench over along period of operation. The hammer can continue to deliver its maximum blows on the collar indefinitely without harmful eiects as the tool construction is steel throughout and the operating parts are of uniform strength and free -of any weakness that will fail under the stress of constant and strenuous use. With all torque strains eliminated due to the free rotative mounting provided in the housing I for the driving collar I3 and the spindle I2, the

operator is not fatigued in the running of the tool and moreover the possibility of serious accidents are entirely avoided. 'I'hus the operator may safely use the tool and hold his body against it, if need be, in cramped quarters vor when standing high in the air on a structural steel or bridge beam without fear of the tool displacing him from his working position.

The rapidity of the hammer blowsprovides considerable power for tightening a nut when applying it or loosening a nut when removing it. Moreover, the speed of these blows rapidly spins a loose nut on or off a bolt as the case may be thus enabling the lwork to be performed rapidly and at a considerable saving in cost.

The cap 4,5 covering' the end of the spindle not in use provides a hand rest for one hand of the operator to hold the wrench` engaged with the work Without contact with the rotating spindle,

The hammering element employed for the wrenchmay be of the impact type desired, it being understood that I do not wish to limit the application of my invention to the use of a chipping or a. riveting hammer as herein referred to. Moreover, the details of construction shown and described may be variously changed and modied without departing from the spirit and scope ofmy invention, except as pointed out'in the annexed claims.

I claim as my invention:

1. A power wrench comprising a housing, a

rotary spindle journaled in said housing and adapted to have a nut driving socket connected therewith, an impact collar revolubly mounted in the housing about said spindle and having ratchet teeth on its inner periphery and an anvil projection on its outer periphery, spring biased pawls carried by the spindle and cooperating with said 'teeth following the blows of the hammer on the collar. Y

2. A power wrench comprising a housing, a rotary spindle journaled in said housing and adapted to have a nut driving socket connected therewith, an impact collar revolubly mounted in the housing about said spindle and having ratchet teeth on its inner periphery and an anvil projection on its outer periphery, spring biased pawls carried by the spindle and cooperating with said teeth for rotating the spindle when the collar is turned in one direction and for releasing the spindle from the' collar when the collar is turned in the opposite direction, a pneumatic hammer connected with the housing and having a piston for imparting blows on the anvil projection for turning the collar in\ a direction to rotate the spindle, and means also operating on the anvil projection for turning the collar in the'o-pposite direction to reset the pawls with respect to said teeth following the blows of the hammer on the collar, said collar being devoid of teeth adjacent the anvil projection to give added strength to the collar at the anvil projection. f

3. A power wrench comprising a housing, a.

rotary spindle-journaled in said housing and adapted to have a nut driving socket connected therewith, an impact collar revolubly mounted in the housing about said spindle and having ratchet teeth on its inner periphery and an anvil projection on its outer periphery, spring biased pawls carried by the spindle and cooperating with said teeth for rotating the spindle when the collar is turned in one direction and for releasing the hammer for turning the collar in the opposite direction to reset the pawls with respect to said teeth following the blows of the hammer on the collar, 'said pawls `beingspaced about 'the spindle for alternate driving engagement 'with said teeth in Athe back and forth turning of the collar.

4. A' power wrench comprising a housing,l a

therewith,v an impact collar revolubly mounted in the housing about said spindle and having an anvil projection, clutch means providing a releasable connection between the collar and the spindle for rotating the spindle when the collar is turned in one direction, a plunger and a tappet reciprocably mounted inthe housing on opposite sides of the anvil projection for contact therewith, a pneumatic hammer connected with the housing and having a piston for delivering blows on the tappet for turning `the collar in a direction to rotate the spindle, and means for subjecting the plunger to the live air pressure of the hammer for forcing the plunger againstthe anvil projection toturn the collar in a direction to reset the clutch connection between the collar and the spindle following the blows of the hammer on the collar.

5. A power wrench comprising 'a housing, a rotary spindle journaled in said housing and adapted to have a nut driving socket connected therewith, an' impact collar revolubly mounted in the housing about said spindle and having an anvil projection, clutch means providing a releasable connection between the collar and the spindle for rotating the spindle when the collar is turned in one directionya plunger and a tappet reciprocably mounted inthe housing on opposite sides of the anvil projection for contact therewith, a'pneumatic hammer having a barrel detachably connected to the housing and containing a piston for imparting blows on the anvil projection for turning the collar in a direction to rotate the spindle, said housing and said barrel having passages communicating at the ,connection between the housing and the barrel for connecting the rear of the plunger with the live-air pressure supply for the hammer for forcing the plunger against the anvil projection to turn the collar lin a direction to reset the clutch connection between thecollar and the Spindle following the blows of the hammer on the collar.

6.\A power wrench comprising a housing, a

having a barrel connected with the housing and containing a piston for imparting blows, on the anvil projection for turning the lcollar in a vdirection to rotate the spindle, a plunger also acting on the anvil projection for turning the collar in the opposite direction to reset the clutchconnection between the collar and the spindle following the blows of the hammer on the collar, said (iD/hammer having a throttle valve for controlling rotary spindle journaled in said housing 'and' adaptedv to have a nut driving socket connected therewith, a driving member revolubly mounted .in the housing with respect to said spindle and having an anvil projection, clutch means providing-a releasable connectionbetweenthe driving member and the spindle for lrotating the spindle -when the driving member is turned in one drection, a pneumatic hammer having abarrel connected with the housing and containing a` piston for imparting blows on the lanvil projec-f, tion for turning the driving member in a direction to rotate the spindle, and a plunger connected with and actuated by the live air-pressure supplied to the hammer for turning the driving member in the Opposite direction to reset the clutch connection between the driving member and the spindlefollowing the blows of the hammer on the driving member, said barrel extending outwardly from the housing in Jged transverse relation to the axis of the spindle and providing a permanent handle member :for the wrench.

8. A power wrench comprising a housing, a rctary spindle journaled in said housing, an im pact collar -revolubly mounted in the housing about said spindle and having an anvil projection, clutch means providing a releasable connection between the collar and the spindle for rotating the spindle when the collar is turned in one direction, a pneumatic hammer connected with said housing and having a piston for imparting blows on the anvil projection for turning the collar in a direction to rotate the spindle, and means operable by the pressure fluid'iurnished to the hammer for turning the collar in the opposite direction to reset the clutch connection between the collar and the spindle following the ,blows of the hammer on the collar, said spindle having its opposite ends accessible from the exterior of the housing whereby a nut driving socket may be connected with one' end of the spindle for al'lplyir'igv a nut or be connected with the opposite end of thethe spindle when the collar is turned in one di- Y rection, a pneumatic hammer connected with the housing and having a piston for imparting blows on the anvil projection for turning the collar in a direction to rotate the spindle, means operable by the pressure fluid furnished to vthe-hammer for turning the collar in the opposite direction to reset the clutch'connection between the collar and thefspindlefollowingthe blows of the ham'- mer on the collar, said yspindle having its opposite ends accessible exteriorly of the housing whereby y'either end Aof the spindle may be equipped with a nut driving'socket, and a protective cap ttable over either end of the spindle .and having releasable connection with' the housing. Y 10. A power wrench comprising a housing, a rotary spindle journaled in said housing and adapted to have a. vnut driving socket connected therewith, an impact collar revolubly mounted in the housing about/said spindle vand having anl anvil projection, clutch means providinga releasable connection between the collar and the spindle forv rotating the spindle when the collar is turned in one direction, a, pneumatichammer' -connected with -the housing and having apiston for imparting'blows on the anvil projection for turning the collar in a directionto rotate the spindle, means operable by the pressure fluid fur- '.nished to the hammer for turning the collar -in *the-opposite' direction for resetting the vclutch connection `between the lcollar and the spindle following the blows of the hammeron the collar, and means for checking the rotation of the v spindle with the collar in the movement of the collar to reset the clutch means.

v11. A power wrench comprising a housing, a rotary spindle journaled in said housing and adapted to have a nut driving socket connected therewith, an impact collar revolubly mounted in the housing abou t the spindle and having an anvil projection, pawl and ratchet means providing a releasable clutch connection between the collar and the spindle'for rotating the spindle when the collar is turned in one direction, a pneumatic hammer connected with the housing and having a piston for imparting blows on the anvil projection for turning the collar in a direction to rotate the spindle, means operable by the pressure fluid furnished to the hammer for turning the collar in the opposite direction to reset the pawl and ratchet connection between the lthe housing about the spindle and having an anvil projection, clutch means providing areleasable connection between the collar and th'e spindle for rotating the spindle when the collar is turned in one direction, a pneumatic hammer connected with the housing and having a piston for imparting blows on the anvil projection for turning the'collar in4 a direction to rotate the spindle, means also operating on the anvil projection for turning the collar in the opposite direction for resetting the clutch connection between the collar and the spindle following the -blows of the hammer on the collar, a non-rotative ring carried bythe housing about the spindle and having cam-shaped recesses facing the spindle, and spring biased rollers located in said recesses to check the rotation of the spindle with the col-- lar in the movement ofthe collar to reset the clutch means. v

13. A power wrench comprising a housing, a rotary spindle journaled in said housing and adapted to have a nut driving socket connected therewith, an impact collarl located in the housing about the spindle and having ratchet teeth on its inner periphery and an anvil projection on its l outer periphery, said housing having a pair of intersecting chambers, one chambe surrounding the spindle and providing a rotative mounting for the collar and the other chamber being offset from the spindle to accommodate the anvil projection, a tappet and a plunger extending into the last named. chamber on opposite sides of the anvil projection for contact therewith, spring biased pawls carried by the spindle and cooperating with said teeth to provide a releasable connection between the collar and the spindle for rotating the spindle when the collar is turned in one direction, a pneumatic hammer connected with the housing about the tappet and having a piston for delivering blows on the tappet for turning the collar in a `direction to rotate the spindle, and,` means connecting the rear of the plunger to the live air pressure of the hammer for forcing the plunger against the anvil projection to turn the collar in a direction to reset the pawls with respect to the teeth following the blows of the hammer on the collar.

14. A portable power wrench comprising a housing, a rotary spindle and an intermittent grip device for driving the spindle, both journaled in the housing, a pneumatic hammer having a barrel connected to the housing and containing a piston for imparting blows on the grip device for turning the latter in a direction to rotate the the spindle, and pressure responsive means carried by the housing and co-operating with the grip device for turning the same in the opposite direction following the blows of the piston, said, pressure responsive means being connected with and operated'by the live air pressure supplied to the hammer.

15. A portable power wrenchcomprisingiA a housing, a rotary spindle and an intermittent,

grip device for driving the spindle, a pneumatic hammer having a barrel connected to the housing and containing a piston for imparting blows on the grip device for -turning the latter in a direction to rotate the spindle, pressure responsive means carried by the housing and co-operating with the grip device for turning the same in the opposite direction following the blows of Y the piston, said pressure responsive means being` connected with and operated by the live air pressure supplied to the hammer, and means providing a rotatable mounting in the housing for the spindle and the grip device, whereby to relieve the housing and the hammer barrel of torque strains of the spindle.

16A portable power wrench comprising a housing, a rotary spindle and an intermittent grip device for driving the spindle, both journaled in the housing, a pneumatic hammer. having a barrel connected to the housingand `containing a piston for imparting blows on the grip device for turning the latter in a direction to rotate the spindle,and pressure responsive means carried by the housing and co-operating with the grip device for turning the same in the op-- posite direction following the blows of the piston, said pressure responsive means being connected with and operable by the live air pressure supplied to the hammer, the latter being ixedly secured to the' housing and having its barrel extending outwardly therefrom whereby the hammer provides a permanent handle member for the wrench. e

17. A portable power wrench comprising a housing, a rotary spindle and an intermittent lgrip device for driving the spindle, both jour- `aled in the housing, and a pneumatic hammer and a pressure actuated means carried by the housing and operable on the grip device for turning the same in opposite directions,- said pressure actuated means being connected with and operated by the live air pressure supplied t'o the l hammer, said grip device having a connection with thespindle for converting the reciprocatory action of the hammer into a rotary Iaction for the spindle, and said spindle having its opposite 75 collar in a direction to rotate the spindle, and

means carried by the housing and operable on the collar in opposition to the piston for turning the collar in a direction to reset the grip device following the blows of the hammer, ysaid hammer being fixedly secured to the housing and extending outwardly therefrom to serve as a permanent handle member for the wrench and disposed in substantially co-planar relation with the collar.

CECIL N. DOUGLASS. 

